System for recycling asphalt millings and methods thereof

ABSTRACT

A system for recycling asphalt millings and methods thereof are provided. In exemplary embodiments, an apparatus for recycling asphalt millings may comprise a blender comprising a basin having an interior volume, an agitator disposed within the interior volume, the agitator adapted to agitate asphalt millings, a blender grate disposed on the bottom of the basin, the blender grate comprising apertures adapted to allow bitumen to pass through the blender grate, a heating conveyor comprising a heating apparatus for heating the asphalt millings, a cooling conveyor comprising an input for receiving asphalt millings and an opening adapted to receive a cold material applicator, a cold material applicator disposed in the opening, the cold material applicator adapted to apply cold material to asphalt millings.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of application Ser. No.14/031,027, filed Sep. 18, 2013, “System for Recycling Asphalt Millingsand Methods Thereof,” which claims priority to U.S. Provisional PatentApplication Ser. No. 61/702,524, filed Sep. 18, 2012, the disclosures ofwhich are incorporated herein by reference in their entirety.

BACKGROUND Field of the Invention

Embodiments of the present invention are generally related to a systemfor recycling asphalt millings and methods thereof. More specifically,embodiments of the present invention relate to a system for removingbitumen from the stone found in asphalt millings so that the stone maybe recycled and/or reused for future applications.

Description of Related Art

Bituminous concrete, otherwise and more commonly known as asphaltmillings, are a common environmental concern during any roadconstruction or similar asphalt construction project. The problem withasphalt millings is that the bitumen binder used in asphalt pavingapplications contains a relatively large concentration of a family ofcarcinogenic compounds which can pose serious human health andenvironmental concerns in certain circumstances such as when asphaltmaterial is ground into very small particles that easily blow off of orwash from the surface.

These compounds, known as polycyclic aromatic hydrocarbons (PAHs) arespecified as targeted pollutants by the U.S. Environmental ProtectionAgency (USEPA), and are present in asphalt at much higher levels thanthe criteria established by most states for general use in a loosefashion on land. Asphalt millings used alone without a paved top surfacehave the potential to significantly migrate from the roadway through theactions of water, wind, and physical displacement and possiblycontaminate surrounding soils and/or surface water sediments. Traffictraveling on the unpaved asphalt millings would generate dust containingthe compounds referenced above and the dust would be a major migrationroute of the millings to the surrounding environment.

Several uses in of asphalt millings are fully appropriate in accordancewith many state's regulations for recycling and beneficial use. However,the use of loose unbound asphalt millings on land and roadway surfaceswithout the placement of a paved top surface is not generallyappropriate; and millings should not be used where runoff to surfacewater features would be possible in order to prevent sedimentcontamination. As such, asphalt millings are not considered clean fill.

Many states permit millings may be taken directly to and used by roadasphalt manufacturing plants for direct incorporation into asphalt(bituminous concrete), pursuant to recycling exemption for such usewhich limits the amount of millings per new asphalt that can be used,which can often be 20% or less. As such, for every ton of asphaltmillings, there needs to be at least five tons of new asphalt in whichto incorporate the millings. Viewed from a different perspective, atleast 80% of asphalt bitumen is effectively wasted from reuse due tostate environmental restrictions.

As such, there is a need for a system for recycling asphalt millings andmethods thereof.

SUMMARY

Embodiments of the present invention are generally related to a systemfor recycling asphalt millings and methods thereof. In one embodiment,an apparatus for recycling asphalt millings is provided that maycomprise a blender comprising a basin having an interior volume; anagitator disposed within the interior volume, the agitator adapted toagitate asphalt millings; a blender grate disposed on the bottom of thebasin, the blender grate comprising apertures adapted to allow bitumento pass through the blender grate; a heating conveyor comprising aheating apparatus for heating the asphalt millings; a cooling conveyorcomprising an input for receiving asphalt millings and an openingadapted to receive a cold material applicator; a cold materialapplicator disposed in the opening, the cold material applicator adaptedto apply cold material to asphalt millings.

In another embodiment of the present disclosure, an apparatus forrecycling asphalt millings is provided that may comprise a ribbonblender comprising a basin having an interior volume; an agitatordisposed within the interior volume, the agitator adapted to agitateasphalt millings; a blender grate disposed on the bottom of the basin,the blender grate comprising apertures adapted to allow bitumen to passthrough the grate; a paddle conveyor comprising a heating apparatus forheating the asphalt millings; a screw conveyor comprising an input forreceiving asphalt millings and an opening adapted to receive a jet; anda jet disposed in the opening, the jet adapted to apply cold material toasphalt millings.

In yet another embodiment of the present disclosure, method forrecycling asphalt millings is provide that may comprise: providing anapparatus for recycling asphalt millings that may comprise a blendercomprising an agitator; a heating conveyor comprising a heatingapparatus; and a cooling conveyor comprising a cold material applicator;adding the asphalt millings to the blender; agitating the asphaltmillings with the agitator and producing initially cleaned millings;adding the initially cleaned millings to the heating conveyor andheating the initially cleaned millings to produce heated millings;adding the heated millings to the cooling conveyor; applying a coldmaterial to the heated millings via the cold material applicator toproduce substantially clean stone.

BRIEF DESCRIPTION OF THE DRAWINGS

So the manner in which the above-recited features of the presentinvention can be understood in detail, a more particular description ofembodiments of the present invention, briefly summarized above, may behad by reference to embodiments, which are illustrated in the appendeddrawings. It is to be noted, however, the appended drawings illustrateonly typical embodiments of embodiments encompassed within the scope ofthe present invention, and, therefore, are not to be consideredlimiting, for the present invention may admit to other equally effectiveembodiments, wherein:

FIG. 1 depicts a photograph an exemplary apparatus for recycling asphaltmillings in accordance with one embodiment of the present invention;

FIG. 2 depicts a flowchart of a method of recycling asphalt millings inaccordance with one embodiment of the present invention;

FIG. 3 depicts a photograph an exemplary apparatus for recycling asphaltmillings in accordance with one embodiment of the present invention;

FIG. 4A depicts a photograph an exemplary apparatus for recyclingasphalt millings in accordance with one embodiment of the presentinvention;

FIG. 4B depicts a photograph an exemplary apparatus for recyclingasphalt millings in accordance with one embodiment of the presentinvention;

FIG. 5 depicts an exemplary blender for recycling asphalt millings inaccordance with one embodiment of the present invention;

FIG. 6 depicts an exemplary agitator for recycling asphalt millings inaccordance with one embodiment of the present invention;

FIG. 7 depicts an exemplary apparatus for recycling asphalt millings inaccordance with one embodiment of the present invention;

FIG. 8 depicts an exemplary apparatus for recycling asphalt millings inaccordance with one embodiment of the present invention; and

FIG. 9 depicts a flowchart of a method of recycling asphalt millings inaccordance with one embodiment of the present invention.

The headings used herein are for organizational purposes only and arenot meant to be used to limit the scope of the description or theclaims. As used throughout this application, the word “may” is used in apermissive sense (i.e., meaning having the potential to), rather thanthe mandatory sense (i.e., meaning must). Similarly, the words“include”, “including”, and “includes” mean including but not limitedto. To facilitate understanding, like reference numerals have been used,where possible, to designate like elements common to the figures.

DETAILED DESCRIPTION

Embodiments of the present invention are generally related to a systemfor recycling asphalt millings and methods thereof. More specifically,embodiments of the present invention relate to a system for removingbitumen from the stone found in asphalt millings so that the stone maybe recycled and/or reused for future applications.

FIG. 1 depicts a photograph an exemplary apparatus 100 for recyclingasphalt millings in accordance with one embodiment of the presentinvention. As shown in the figure the apparatus 100 generally comprisesa churning drum 110 having an interior volume, a burner assembly 120 forheating the drum 110 and the contents therein, and a plurality ofbrushes or paddles 130 for churning the contents of the drum 110. Thedrum 110 may comprise any size or shape voluminous body suitable forembodiments of the present invention as described herein. In variousembodiments, the drum 110 may be as small as a few cubic feet to aslarge as thousands of cubic feet in size.

The burner assembly 120 may comprise any type of burner suitable to heatthe drum and the contents therein, as described herein below. In manyembodiments, the burner assembly 120 comprises a propane burner,connected to a source of fuel (not shown), and capable of maintain aconstant flame over a substantial period of time. In furtherembodiments, electric burners, natural gas burners, or the like may beutilized.

The plurality of brushes or paddles 130 may comprise any number ofdevices necessary to adequately churn the contents of the drum duringuse. In one embodiment, the plurality of brushes or paddles 130comprises a set of angled brushes positioned on arms extending from acentral shaft. As the central shaft rotates, the brushes also rotate,churning the contents of the drum. In another embodiment, paddles may besimilarly positioned such that as a central shaft rotates, the paddleslift and move any of the contents within the drum. As a number ofsolutions may exist, and may be generally known, for providing a set ofbrushes, paddles, fins, or the like, to churn contents within avoluminous body, any of such solutions may be suitable for variousembodiments of the present invention.

In certain embodiments, the drum 110 may comprise an outlet 112 forpermitting the bitumen to exit the drum 110. As shown in the Figure, inone embodiment, the outlet 112 may comprise a slit or slot down a sideof the drum. In the embodiment depicted, the outlet 112 may be coupledwith a channel or fin 114 for directing the exiting bitumen towards awaste collection area (not shown). In alternative embodiments, theoutlet 112 may comprise a filtered outlet system comprising pipesdirecting exiting bitumen/water to further be filtered through anynumber of filtering processes (e.g., a water vapor filtration system toseparate any water from the bitumen residue).

In further embodiments of the present invention, the apparatus 100 maycomprise a means for stone removal after the bitumen has been separated.In one embodiment, such means for stone removal may comprise paddles (asdescribed above), which may lift the stone in the normal course, andupon positioning of a chute or similar structural device, the stone maybe removed from the drum 110. Alternatively, the means for stone removalmay comprise a separate outlet on the drum 110, which may permit a userto open the outlet after the bitumen has been removed, and the stone andliquid may be further separate through any number of filtrationprocesses.

In accordance with many embodiments of the present invention, theapparatus 100 must generally operate in connection with a liquid mixturein order to cleanse and recycle the asphalt millings. The liquidmixture, generally shown as liquid 140, comprises a combination ofwater, oil (such as mineral oil, peanut oil, vegetable oil, or thelike), and a chemical composition, such composition generally comprisinga mixture of water, sodium lauryl sulfate, sodium laureth sulfate,lauramine oxide, alcohol denatured, sodium chloride, copolymers,phenoxyethanol, magnesium chloride, methylisothiazolin one andtriclosan. In many embodiments, the chemical composition added to theliquid mixture may be obtained commercially as a form of dish soap.

Generally, the amount of liquid mixture provided is dependent upon theamount of asphalt millings needed to be cleansed or recycled. Forexample, in one embodiment, for every nine cubic feet of asphaltmillings, the liquid mixture may comprise approximately seven to tengallons of water, approximately 3 to 5 ounces of oil, and approximately3 to 5 ounces of chemical composition. It should be appreciated,however, variations of the ratios of ingredients herein may be modifiedsubstantially (e.g., 500% or more) without departing from the scope ofembodiments of the present invention.

FIG. 2 depicts a flowchart of a method of recycling asphalt millings inaccordance with one embodiment of the present invention. The method 200begins at step 210 where an apparatus, such as the apparatus describedin FIG. 1 is provided.

At step 220, the liquid mixture ingredients are added to the drum of theapparatus. In exemplary embodiments, seven to ten gallons of water,approximately 3 to 5 ounces of oil, and approximately 3 to 5 ounces ofchemical composition are added to the drum. It should be appreciated,however, the quantities provided herein should not be deemed limiting inany capacity to the scope and future embodiments of the presentinvention, and are merely indicative of the exemplary and experimentalembodiments conducted.

At step 230, the liquid mixture is preheated in the drum via the burner.In many embodiments, the liquid mixture is preheated to approximatelybetween about 125 deg. F. to about 225 deg. F. In other embodiments, theliquid mixture is preheated to between about 140 deg. F. to about 160deg. F. For many applications, it may be undesirable to heat the liquidmixture to a boiling temperature, as boiling may cause the water in themixture to vaporize, thus changing the ratios of ingredients in thecomposition.

At step 240, asphalt millings are added to the apparatus. In oneembodiment, given the amount of liquid mixture provided, about 9 cubicfeet of asphalt millings may be added to the drum. However, inalternative embodiments, the amount of asphalt millings added may bedependent upon the size of the drum and its capabilities.

At step 250, the millings and liquid mixture composition arecontinuously heated and stirred/mixed within the drum. In manyembodiments, the contents of the drum are heated to between about 135deg. F. and about 225 deg. F. In one embodiment, the contents of thedrum may be heated to between about 150 deg. F. to about 200 deg. F. Theheating and stirring process at step 250 may continue for at least 30minutes to as long as 48 hours. In the exemplary embodiment describedherein, at the quantities shown, the heating and stirring process maytake between about 45 minutes to 90 minutes.

At step 260, the stone of millings and the bitumen may begin toseparate. As the stone and bitumen begin to separate, the stone remainsat or near the bottom of the drum (given its weight) and the bitumen maygenerally float within the liquid mixture. As such, while the brushes orpaddles are rotating, the bitumen will be pushed out the outlet of thedrum. As soon as the bitumen has been removed, the stone may also beremoved from the drum and permitted to dry. The method ends at step 270.

The resulting stone from the method 200 may generally be substantiallyfree of any bitumen or undesirable oils. In many embodiments the stonemay be at least 90% bitumen free. In further embodiments, the stone maybe at least 98% bitumen free. In certain instances, it may be desirableto add a further cleansing/soaking process for the stone which mayeliminate any residual bitumen thereon. As such, in at least oneembodiment, the resulting stone from the processes described herein, maybe at least 99.9% bitumen free.

FIG. 3 depicts a photograph an exemplary apparatus 300 for recyclingasphalt millings in accordance with one embodiment of the presentinvention. In exemplary embodiments, the apparatus 300 comprises ascreen drum 308. The screen drum 308 may be adapted to separatematerials by size, for example, separating different sizes of crushedstone or separating liquid, sand, glass, bitumen, and/or the like fromstone. In some embodiments, the screen drum 308 may comprise a trommel,or the like. The screen drum 308 may comprise a screened cylinderadapted to separate stone in asphalt millings from another material whenrotated.

The screen drum 308 may generally comprise a shaft 304, one or morescreen paddles 306 and a screen grate 302, and/or the like. The shaft304 may run through the center of an interior cavity of the screen drum308. In some embodiments the shaft 304 may run through a location closerto the sides of the drum 308 and/or may simply be connected with to anexterior surface of the drum 308 and adapted to rotate the drum whenmoved by another mechanical or electrical force. In some embodiments,more than one drum 308 may be included in the apparatus 300. In someembodiments, more than one shaft 304 may be included. The drum 308 maygenerally comprise a diameter of between 18 inches and 68 inches, butmay also comprise much larger drum, for example, 20 feet in diameter, orthe like. In various embodiments, the drum 308 may be as small as a fewcubic feet to as large as thousands of cubic feet in size.

The screen paddle 306 may be adapted to move, churn, and/or sift throughmaterial within the interior of the drum 308. By way of example thescreen paddle 306 may be adapted to move liquid, asphalt millings,bitumen, and/or the like so that it does not stay stagnant within thedrum 308 and stick or attach to an interior surface of the drum 308. Insome embodiments, the screen paddle 306 may be attached to the shaft 304in an interior cavity of the drum 308. In some embodiments, more thanone screen paddle 306 may be included in the drum 308. The screen paddle306 may be attached to a paddle connector 307 that may comprise a flatand/or rounded connector that connects the paddle 306 to the shaft 304and/or the like. In some embodiments, the paddle connector 307 may beextend from the paddle 306 on one side of the interior cavity of thedrum 308 all the way to an opposite side of the interior cavity of thedrum 308. In some embodiments, the connector 307 may extend less thanthe entire distance between two sides of the drum 308 and/or mayterminate at the shaft 304. Although pictured as a rectangle, the paddle306 may comprise any feasible shape adapted to move materials around onthe interior of the drum 308. In some embodiments, more than one paddle306 and/or more than one paddle connector 307 may be included. In someembodiments, the paddle 306 may be attached directly to the shaft 304and/or directly to an interior surface of the drum 308. The drum 308 maybe included in any process described herein, including the methoddescribed above with respect to FIG. 2. For example, the drum 308 may beincluded before and/or after the millings are added to the churning drum110.

The screen grate 302, may comprise holes and/or apertures adapted toseparate larger materials from smaller materials that come into contactwith the grate 302. For example, the grate 302 may comprise holes and/orapertures of a sufficient size to allow a liquid, bitumen, sand, glass,or smaller materials to pass through the grate 302, while retaininglarger items, for example, pieces of asphalt millings. The grate 302 maybe positioned on one side of the drum 308 or may comprise the entireoutside surface of the side of the drum 308. In some embodiments, thegrate 302 may be closeable with an exterior closing means and/or door(not shown). The closing means may be adapted to cover the grate 302 andprevent any material from exiting the drum 308, thereby allowing thematerials inside the drum 308 to mix when the drum 308 is rotated withthe shaft 304 and/or the like. The grate 302 may comprise steel or amaterial of sufficient strength to resist bending, deforming, and orbreaking when contacted with stones and/or asphalt millings that fill asubstantial portion of the interior of the drum 308. In someembodiments, a screw conveyor (not shown) may be included to transportthe millings and/or bitumen to and/or from the drum 308 to anothercomponent of the apparatus 300. In some embodiments, a heating member(not shown), such as a burner assembly, may be disposed adjacent to,near, or underneath the screen drum 308 to heat up the bitumen, asphaltmillings, and/or other liquids present inside the drum 308 beforetransporting the material to a separate portion of the apparatus 300.

FIGS. 4A and 4B depict a photograph an exemplary apparatus 300 forrecycling asphalt millings in accordance with one embodiment of thepresent invention. In exemplary embodiments, the apparatus may comprisea conveyor 350. A conveyor 350 may comprise a conveyor paddle 322, teeth323, a conveyor screen 324, a conveyor shaft 326, a side wall 328,and/or the like. In exemplary embodiments, the conveyor 350 may beadapted to move materials, such as asphalt millings and bitumen along apath. In some embodiments, the path may comprise an incline between 1and 90 degrees.

In accordance with exemplary embodiments, the conveyor 350 may transportsmaller portions of asphalt millings and bitumen along the conveyor in arelatively spread out configuration, so that each paddle 322 may carry aportion of asphalt millings and/or bitumen received from either thechurning drum 110, the screen drum 308, and/or the like. In exemplaryembodiments, the conveyor 350 may be adapted to receive the asphaltmillings, bitumen, and/or the like after it has been heated. Forexample, the asphalt millings, bitumen, and/or the like may be heated inthe churning drum 110 and/or the screen drum 308 prior to beingtransported to the conveyor 350.

In some embodiments, the conveyor 350 may comprise a means fordisbursing liquid nitrogen, dry ice, and/or the like (not shown). Inexemplary embodiments, the apparatus 300 may comprise jets (not shown)or a disbursement means adapted to spray or otherwise apply liquidnitrogen, dry ice, and/or the like to heated asphalt millings, bitumen,and/or the like that is being transported on the conveyor 350. In someembodiments, the jets or other disbursement means may be configured toapply liquid nitrogen, dry ice, and/or the like at a sufficient forcesuch that bitumen and is separated from stone of asphalt millings whenit is applied.

In some embodiments, the temperature differential between the heatedasphalt millings and bitumen and the applied liquid nitrogen, dry ice,and/or the like, may cause the bitumen to separate from the stone of theasphalt millings. When the bitumen is separated from the stone of theasphalt millings, it may be filtered through the conveyor screen 324 toa collection means (not shown), such as a tank, a channel, an outlet,and/or the like. The remaining stone of the asphalt millings maycontinue to be transported by the conveyor paddles 322 and placed in asecond collection means, such as a tank, a box bed of a dump truck, afreight car, a storage means, a transportation means, and/or the like.In some embodiments, the liquid nitrogen, dry ice, and/or the like maybe blasted onto the asphalt millings by the jets. In some embodiments,the materials, such as asphalt millings, stone, and bitumen, may beblasted with abrasives by the apparatus 300. The apparatus 300 may beadapted to forcibly propelling a stream of abrasive material against thesurface of the materials under high pressure to extract the bitumen fromthe asphalt millings.

In exemplary embodiments, a conveyor paddle 322 may be coupled with aconveyor track, and may be adapted to transport materials, such asasphalt millings and/or bitumen along the conveyor track. The conveyorpaddle 322 may be coupled with one or more teeth 323, a conveyor screen324, a conveyor shaft 326, and/or the like. The conveyor paddle 322 maybe adapted to be moved along the track by the track itself or by aconveyor shaft 326 that moves the paddle 322 along the track when theshaft 326 is rotated. The conveyor paddle 322 may be adapted to hold apredetermined amount of materials and transport the materials at anincline between 1 degree and 90 degrees, and/or the like. The conveyorpaddle 322 may comprise a material of sufficient strength tosubstantially resist deforming, denting, and/or the like whentransporting materials in excess of 500 pounds while being blasted withliquid nitrogen, dry ice, and/or the like. The conveyor paddle 322 maycomprise one or more teeth 323, or the like. The apparatus 300 may beadapted to produce recycled asphalt with an approximately 95%-100%salvage rate.

In exemplary embodiments, the teeth 323 may comprise protrusions fromthe conveyor paddle 322 adapted to separate materials, such as stone ofthe asphalt millings and bitumen, into portions along the transverselength of the conveyor paddle 322, and/or the like. The teeth 323 may bedisposed perpendicular to the paddle 322. The teeth 322 may comprisesubstantially flat members with substantially triangular heads adaptedto push through materials, separate, and/or move materials up theconveyor 350. In some embodiments, the teeth 323 may comprise a degreeof curvature to allow the teeth 323 to transport the material on theconveyor 350. The teeth may be evenly spaced across the transverse spanof the paddle 322 or may be disposed in bunches. The teeth 323 maycomprise material of sufficient strength to substantially resistbreaking and/or bending when transporting heavy materials such asasphalt millings and when being blasted with liquid nitrogen, dry ice,and/or the like. The teeth may be integral with the paddle 322 ore maybe detachably attached for ease of cleaning.

In some embodiments, the conveyor 350 may comprise a conveyor screen324. The conveyor screen 324 may be adapted to transport materials, suchas asphalt and/or bitumen, along the track of the conveyor 350. Thescreen 324 may comprise holes and or apertures adapted to hold asphaltmillings in place while allowing bitumen, liquids, sand, or the like, topass through thereby separating the bitumen from the asphalt millings.The apparatus 300 may comprise a means of collecting the bitumen and thestone of the asphalt millings when they are separated. For example, theconveyor 350 may comprise a basin, tank, and/or the like for collectingboth the stone of the asphalt millings and the bitumen separately. Theapertures may be of sufficient size to allow bitumen to pass throughwhile retaining asphalt millings on the screen 324. The screens 324 maybe attached via a hinge, such that when the screens 324 pass a certainportion of the conveyor 350 they fold down and rotate underneath theconveyor track. In some embodiments, the screens 324 may then fold up toa substantially perpendicular position in relation to a paddle 322, forexample, at the bottom of the track. In some embodiments, when thescreens 324 may fold upwardly to transport materials up the track of theconveyor 350.

In some embodiments, the conveyor 350 may comprise conveyor shaft 326.The conveyor shaft 326 may be adapted to move the conveyor paddles 322along the track of the conveyor 350. In some embodiments, the conveyorshaft 326 may be coupled with a track of the conveyor such that rotationof the conveyor shaft 326 causes the paddles 322 to move along thetrack. Although one conveyor shaft 326 is shown, more than one conveyorshaft 326 is contemplated by and within embodiments of the presentdisclosure. The conveyor shaft 326 may comprise a material adapted topull the conveyor paddles 322 along the track of the conveyor 350 whilethe paddles 322 are transporting materials, such as asphalt millingsand/or bitumen. In some embodiments, the conveyor 350 may comprise aside wall 328. The side wall 328 may be disposed on lateral sides of theconveyor 350 and may be adapted to retain materials, such as asphaltmillings and/or bitumen, within the side walls.

FIG. 5 and FIG. 6 depict an exemplary blender 500 for recycling asphaltmillings in accordance with one embodiment of the present invention. Insome embodiments, the blender 500 may comprise a blender basin 502, ablender grate 504, an agitator 506, and helical blades 508, or the like.In exemplary embodiments, the blender 500 may be used in conjunctionwith any component in accordance with the present disclosure. Theblender 500 may general be adapted to accept materials, such as asphaltmillings or the like, and blend the materials in a blender basin 502. Byway of example, the blender 500 may comprise a ribbon blender.

A blender basin 502 may comprise a U-shaped horizontal trough, or thelike. The blender may comprise an agitator 506, such as the one depictedin FIG. 6. In some embodiments, the agitator 506 may comprise a ribbonagitator. In exemplary embodiments, the agitator 506 may comprise a setof inner and/or outer helical blades 508. The outer blades may beadapted to move the materials toward the center of the basin 502, andthe blades may be adapted to move the materials toward the outside ofthe basin 502. In some embodiments, the agitator may be adapted torotates at approx. 200-500 surface feet per minute (SFPM), or the like.In some embodiments, the blender 500 may be adapted to move materialsboth radially and laterally to insure substantially complete blends inrelatively short cycle times. In exemplary embodiments, paddles, ore thelike may be included instead of, or in addition to, the helical blades.

In operation, materials, such as asphalt millings, or the like, areplaced in the blender 500 and blended in the blender basin 502 with theagitator 506. As the asphalt millings rub together, residue attached tothe stones of the asphalt millings, such as bitumen, sand, glass, or thelike, may be removed. As the bitumen is removed, it may pass downwardover one or more blender grates 504 disposed at the bottom of theblender basin 502.

A blender grate 504 may generally comprise apertures adapted to allowresidue like bitumen and sand to pass through the apertures, whileretaining the stones that have been initially cleaned. The asphaltmillings may be initially cleaned, and some materials removed and/orstripped from the stones, in the blender 500 during a blending process.After the blending process is complete, the remaining cleaned asphaltmillings may be taken to another portion of an apparatus for recyclingasphalt millings for further processing. For example, the remainingcleaned asphalt millings may be transported to a conveyor. In someembodiments, the blender basin 502 may be hingedly attached via a hingeand/or slidably attached to track and may be moved for emptying of thebasin 502. For example, the basin 502 may be adapted to tip laterally toempty the contents of the basin 502. In another example, the basin 502may be adapted to slide down a track or rails and empty via a side, thebottom, or the top of the basin 502. An exemplary conveyor is depictedin FIG. 7.

FIG. 7 depicts an exemplary heating conveyor 510 for recycling asphaltmillings in accordance with one embodiment of the present invention. Theconveyor may comprise a conveyor track 514 and a heating apparatus 512.In some embodiments, the heating conveyor 510, such as a grate conveyorand/or the conveyor 350 described above with respect to FIGS. 4A and 4Bmay be used. Alternative types of conveyors adapted to transport asphaltmillings on a conveyor track may be used. In some embodiments, theconveyor track 514 may be flat or may be inclined, as shown in FIG. 7.The angle of incline of the conveyor track 514 may be from about 0degrees to about 90 degrees. In some embodiments, a stationary surfacemay be used instead of a heating conveyor 510.

In exemplary embodiments, a material, for example, cleaned asphaltmillings may be placed on the conveyor and transported along theconveyor track 514. When the materials are disposed on the conveyortrack 514, the heating apparatus 512 may be activated and may heat thematerials. In some embodiments, the heating element may be placed above,below, and/or adjacent the conveyor track 514. Although depicted ascovering the entire length of the top of the conveyor track 514 in FIG.7, the heating apparatus 512 may be disposed on only a portion of thetrack 514. In some embodiments, the heating conveyor 510 may comprise anopen and/or screened bottom for allowing residue, such as bitumen and/orthe like to escape through the bottom of the heating conveyor 510. Insome embodiments, a collection basin and/or channel (not shown) may bedisposed under the heating conveyor 510 for collection of the residuefrom the stones. For example, the heating apparatus 512 may be disposedat the top, at the bottom, in the middle, and/or the like of the track514. In some embodiments, the heating apparatus may comprise the burnerassembly described with respect to FIG. 1.

In exemplary embodiments, a heating apparatus 512 may comprise anelectric and/or gas source of heat, adapted to apply heat 514 tomaterials, such as asphalt millings, or the like. In some embodiments,the heating apparatus 512 may be adapted to produce and direct infraredheat, or the like, on the materials carried or disposed on the heatingconveyor 510. In exemplary embodiments, the heating apparatus 512 maygenerally be adapted to heat the materials, such as asphalt millings, tofrom about 180 degrees Fahrenheit to approximately 250 degreesFahrenheit, or the like. In operation, after the materials, such as theasphalt millings, are heated on the heating conveyor 510 with theheating apparatus 512, the materials may be transported and disposed ona second conveyor, a cooling conveyor 520, and/or the like for a coolingprocess. In some embodiments, a single conveyor may be used for both theheating and cooling process.

FIG. 8 depicts an exemplary cooling conveyor 520 for recycling asphaltmillings in accordance with one embodiment of the present invention. Inexemplary embodiments, a cooling conveyor 520 may comprise a screwconveyor. In some embodiments, the screw conveyor 520 may be adapted totransport raw materials, such as asphalt millings, or the like, throughthe screw conveyor 520 and apply a cold material to the raw materials.In some embodiments, the cold material may comprise a material ofsubstantially low temperature, such as dry ice, liquid nitrogen, or thelike. In exemplary embodiments, the screw conveyor 520 may comprise aninput 522, an opening 524, an output 526, a conveyor grate 528, a screw530, and a screw shaft 532. The screw 530 may be disposed in the centerof the screw conveyor and may be adapted to move materials, such asasphalt millings, through the screw conveyor when the screw shaft 532 isrotated, for example via a mechanical and/or electrical power source.The input 522 may comprise an opening adapted to direct raw materials,such as asphalt millings, into a cavity of the screw conveyor 520. Inexemplary embodiments, the input may receive the raw materials from anycomponents in accordance with the present invention. In one example theraw materials may be fed into the input 522 via a hopper, or the like.

In exemplary embodiments, an opening 524 may be adapted to accept a coldmaterial applicator 534. A cold material applicator 534 may comprise ajet, or the like. In some embodiments, an opening 524 may be adapted toaccept a portion of a jet or the like. For example a jet head may couplewith the aperture. Although depicted as being disposed on the input andon the side of the screw conveyor 520, any number and location ofopenings 524 are contemplated by and within embodiments of the presentinvention. In some embodiments, apertures may provide the jets access tospray, blast, and/or like the raw materials with the cold material. Forexample, dry ice may be blasted onto the raw materials inside the cavityof the screw conveyor 520. A conveyor grate 528 may comprise aperturesadapted to allow residue, sediment, bitumen, sand, glass, and/or thelike to filter through the grate while retaining the remaining cleanedstone. In operation, the heated materials, such as stone, bitumen, andasphalt millings may be fed into the input 522, and a cold material ofsubstantially colder temperature than the heated materials may beblasted onto the heated materials. The screw conveyor 520 may comprisematerial adapted to resist damage during extreme changes in temperature,such as when the heated material is blasted with the cold material. Forexample, heated material may be heated by the heating apparatus 512 to atemperature of 250 degrees Fahrenheit and may be blasted with dry icehaving a temperature of −109 degrees Fahrenheit, a temperaturedifference of approximately 359 degrees Fahrenheit. This extremetemperature difference removes residue, such as sand, oil, bitumen,and/or the like from the stone of the asphalt millings, producing asubstantially clean stone. The substantially clean stone may then betransported, for example, by the screw conveyor 520 and exit the output526. The residue, such as sand, oil, bitumen, and/or the like maygenerally be filtered and drop through the conveyor grate 528 to astorage location. In some embodiments, the output 526 may be disposedoff the edge of the screw conveyor 520 instead of perpendicular to theconveyor 350, as depicted in FIG. 8. As such, the screw conveyor 520 maybe adapted to receive heated asphalt millings and separate the stonefrom bitumen, or the like, by blasting or otherwise applying dry ice, orthe like to the heated asphalt millings. The dry ice then may evaporateleaving little or no environmental waste. After the stone and bitumen,or the like are separated, each may be stored in separate storagelocations (not shown). The process may be completed without utilizingthe drums depicted in FIG. 1 and/or FIG. 3.

FIG. 9 depicts a flowchart of a method 900 of recycling asphalt millingsin accordance with one embodiment of the present invention. The method900 begins at step 910 where an apparatus, such as the apparatusdescribed herein with respect to FIGS. 1 and 3-8 is provided. For easeof illustration and exemplary purposes, the reference numbers of theembodiments described herein are used below. At step 920, asphaltmillings may be added to the blender 500. The blender may be activatedand operated at a sufficient speed to cause the stones of the asphaltmillings to rub against each other and may remove residue, such asbitumen, oil, or the like, from the stone. The residue may be filteredthrough a blender grate 504 and separated from the initially cleanedmillings. The initially cleaned millings may then be removed from theblender 500 and transported to a heating conveyor 510, or the like, fora heating process. In some embodiments, the millings may be placeddirectly on the heating conveyor 510 without being blended by theblender 500.

At step 930, the millings may be heated with a heating apparatus 512, orthe like. In some embodiments, the millings may be heated from aboutapproximately 130 deg. F. to about approximately 350 deg. F. In someembodiments, the millings are heated to between about 160 deg. F. toabout 250 deg. F. The millings may be substantially continuously heatedwhile on the heating conveyor 510 or at a single portion of the heatingconveyor 510. The heating process at step 930 may continue for at least10 seconds to as long as 48 hours. In the exemplary embodiment describedherein, at the quantities shown, the heating process may take betweenabout 45 minutes to 90 minutes. At the end of step 930, the stone of themillings and a portion of the bitumen may separate.

At step 940, the stone and the asphalt millings may be transported aconveyor. In some embodiments, a conveyor described with respect to FIG.4A, 4B, 7, 9, and/or the like may be used. In some embodiments, theconveyor may comprise a screw conveyor 520. The heated contents of oneor more heating conveyor 510 or other containing apparatus may enter onor be collected by the conveyor 520 after the heating process has beencompleted. The conveyor 520 may further separate bitumen form the stoneof the asphalt millings by pressure blasting or otherwise applying acolder material to the heated contents, the colder material having asubstantially lower temperature than the heated contents. In someembodiments, the temperature difference between the heated contents andthe colder material, and/or the applied pressure of the applied coldermaterial being blasted, may cause the stone of the asphalt millings andthe bitumen to separate. For example, dry ice and/or liquid nitrogen maybe blasted, sprayed, or otherwise applied to the heated contents. Insome embodiments, the colder material may be blasted at a force ofbetween 60-200 PSI, for example, 125 PSI. The bitumen, or the like, maybe separated from the stone and may filter through a conveyor grate 528to be collected.

At step 950, the stone of millings and the bitumen may continue toseparate and be placed into a container for collection. As the stone andbitumen separate, the stone may remain in the conveyor and the bitumen,or the like, may generally pass through the conveyor grate 528 to acontaining member, such as a tank, a basin, a barrel, and/or the like.As such, while the heated contents are moving along the track of thescrew conveyor 520, the bitumen will pass out of the conveyor throughthe conveyor grate 528. Once the bitumen has been removed, the stone mayalso be removed from the conveyor and permitted to dry. The method mayend at step 960.

The resulting stone from the method 900 may generally be substantiallyfree of any bitumen or undesirable oils. In many embodiments the stonemay be at least 90% bitumen free. In further embodiments, the stone maybe at least 98% bitumen free. In certain instances, it may be desirableto add a further cleansing/soaking process for the stone which mayeliminate any residual bitumen thereon. As such, in at least oneembodiment, the resulting stone from the processes described herein, maybe at least 99.9% bitumen free.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof. It is also understood thatvarious embodiments described herein may be utilized in combination withany other embodiment described, without departing from the scopecontained herein.

I claim:
 1. A process for recycling asphalt millings, said asphaltmillings comprised of stone and bitumen, the process comprising thesteps of: heating said asphalt millings; applying cold air to saidasphalt millings after said step of heating said asphalt millings; andseparating said stone from said bitumen after said step of applying coldair thereto.
 2. The process of claim 1 further comprising the step ofblending said asphalt millings in a blending apparatus prior to saidstep of heating said asphalt millings.
 3. The process of claim 1 whereinsaid step of separating said stone from said bitumen comprises the stepof passing said bitumen through a grate.
 4. The process of claim 1further comprising the step of pretreating said asphalt millings priorto said step of heating said asphalt millings.
 5. The process of claim 4wherein said step of pretreating said asphalt millings comprises thestep of cleaning said asphalt millings in a liquid.
 6. The process ofclaim 5 wherein said liquid is comprised of water, oil and a chemicalselected from the group comprising sodium lauryl sulfate, sodium laurethsulfate, lauramine oxide, alcohol denatured, sodium chloride,copolymers, phenoxyethanol, magnesium chloride, methylisothiazolinoneand triclosan.